$OpenBSD: patch-src_Network_ATC-Main_cxx,v 1.1 2015/03/21 01:02:11 pascal Exp $
--- src/Network/ATC-Main.cxx.orig	Sat Jan  3 21:33:30 2015
+++ src/Network/ATC-Main.cxx	Sat Jan  3 21:34:10 2015
@@ -39,6 +39,7 @@
 #endif
 
 #include <string>
+#include <unistd.h>
 
 #include <simgear/debug/logstream.hxx>
 #include <simgear/props/props_io.hxx>
